The line translates as "You too, Brutus?". However, Shakespeare, great a poet though he was, knew very little Latin (if any at all), and in this line inaccurately paraphrased the line Suetonius put in as Caesar's last words: "Kai sy, teknon?" which is the Greek for "You too, descendent?" or "You too, child?" (It was common gossip in Rome that Brutus was Caesar's illegitemate child).

The fact that Suetonius claims that Caesar's last words were Greek and not Latin, should not strike us as a great surprise, as many (if not the vast majority) of the Roman nobility (the Patricians), were brought up by Greekslaves and quite often spoke and wrote Greek long before Latin.